1. Technical Field
This invention relates to devices used to keep individual's feet warm during long outdoor activities such as hunting. Electric resistant heating wires are used to generate heat from a portable electric source.
2. Description of Prior Art
Prior art devices of this type have relied on a variety of different designs attempting to heat footwear by electric resistant cells. See for example U.S. Pat. No. 3,906,185, U.S. Pat. No. 3,360,633 and U.S. Pat. No. 2,692,326.
In U.S. Pat. No. 2,692,326, a heated shoe is disclosed having a heating element within the sole of the shoe. Vent openings are provided in the upper sole portion to allow heat to pass upward from the interior of the shoe.
U.S. Pat. No. 3,360,633 discloses a portable heating apparatus having a platform in which is contained batteries and a heating resistant film. A strap is used to secure the platform to the foot of the wearer with the heating film positioned on the concave platform support portion.
In U.S. Pat. No. 3,960,185 a heated insole construction is shown having a layer of plastic mesh material with an overlying plastic mat with an electrically conductive circuit printed thereon. A cloth layer covers the conductive circuit material.